i have a question (not related to the creationist nonsense), and i don’t feel like researching it to find the answer (i’m in my lab, doing research, it’s not like i’m against looking things up; i’m just not a biologist).

i figure there must be a term in evolutionary biology referring to the proportion of a given generation that manages to produce offspring. what is this called? i’d like to read about it.

Christianity has been proven wrong, everyone knows that. No one has been able to show an example of physical evidence of Jesus’ existence, let alone historical Jesus.

JC, you sort of missed the point. Oh wait, you ARE the point: you’re a parrot, spouting lies and nonsense, just like your coreligionists portrayed in the video. You’re wrong and you’re either stupid or a liar, and everyone who read your comment (even your fellow fundies) knows that.

Wayne: JC doesn’t care. His brain, at least in matters related to biology, has been zombified. There is no room there for judgement or critical thought. Thanks for the link, but I wonder if any fundie anywhere has ever changed their opinion in the face of the massive evidence for evolution. Especially the sort of fundie/troll who lurks here waiting to make an asinine comment.

Let me know if you think I’m wrong about this, but instead of arguing with such trash, I prefer to say “Fuck you!” It’s much less frustrating than trying to have a discussion with someone who’s not discussing in good faith.

@andrew: I think the term you’re looking for is reproductive fitness. Individuals that reproduce more than others in a given population are considered more “fit” because a higher proportion of their genes have been transmitted to the next generation. Evolution occurs through a change in gene frequency in a population over time. It works the same way whether you’re talking about paramecia, petunias, or people (though, obviously, how those genes are transmitted happens a little differently depending on the species).

so, given a certain population of individuals, can you estimate fitness for an individual (not knowing what particular combination of genes he’s got from the population)?

if you’re talking about a whole population (e.g. “all the humans”), rather than about a particular genotype carried by some humans and not by others, is fitness equivalent to growth rate (i.e. you want the value above 1.0)?

“If Atheists Ruled the World”….it would probably look a bit like today’s Scandinavian countries. Read the (unfortunately quite expensive) “Society without God: What the Least Religious Nations Can Tell Us About Contentment” by Phil Zuckerman.
And if the Religious Right needs more proof of how horrible Scandinavia is, read this recent article: “Swedish lab develops genital herpes vaccine” http://www.thelocal.se/25574/20100317/ — after all, we all know that God created stuff like HIV and Herpes as a just punishment for all those who do not practise celibacy.

given a certain population of individuals, can you estimate fitness for an individual (not knowing what particular combination of genes he’s got from the population)?

No, if you don’t have any variables to work with any estimate you make would be total guesswork for that individual. But you could develop probabilities in specific cases (but even then you would need to know the gene frequencies for the population). This is actually pretty simple. So, for example, if you know your child is a carrier for sickle cell anemia (i.e. has one recessive allele for that trait, or ‘Aa’) what would be the likelihood of your grandchild getting the disease? You would need to use the disease frequency in the general population to estimate the number of other carriers.

The Hardy-Weinberg principle is simply p + q = 1 (where p is the frequency of allele ‘A’ and q is the frequency of allele ‘a’). The frequency of those with the disease in the United States is 1:1000 (or 0.1% of the population) and you know they all have two recessive alleles (‘aa’ with a frequency of p-squared), so therefore the frequency of allele ‘a’ is 0.03175. But since you can eliminate those who have the disease (‘aa’) we need to find out the frequency of other carriers (‘Aa’).

To determine the frequency of the heterozygote (‘Aa’) we use the algebraic formula p-squared + 2pq + q-squared = 1.

The frequency of allele ‘A’ is 0.96825, so the frequency of people that are not carriers (‘AA’) is 0.9375 and the frequency of carriers (‘Aa’) is 0.0615. Six percent of the population are also carriers for sickle cell anemia. But since you could only have a child with half of them, that means there is a 3% chance your grandchild will be conceived by two carriers.

But even then there is only a 1 in 4 chance that two ‘Aa’ parents would have a child with the ‘aa’ trait. So the odds that your grandchild would get sickle cell anemia is about 1:130. Naturally, this gets complicated once you start factoring in higher frequencies in different populations and trying to account for multiple alleles, but I think you get the general idea.

@Shashank: No, atheists can’t prove either the existence or nonexistence of God and neither can you. What atheists choose, given the weight of evidence that the universe operates based on natural principles and the incredible inconsistencies within religious dogma, is to not believe in God. Theism is the belief in a God or gods and atheism is the lack of such belief. It has nothing to do with proof. We’re all atheists where it comes to Zeus and Thor, and I’m confident that you don’t feel the need to prove Thor doesn’t exist. Some of us merely take it one god further.

You might want to try “relative fitness.” It’s the fitness of the individual on a scale from 0 to 1, in comparison to the “fittest” class of individuals in the population. You take the survivorship rates of all the “classes” of individuals and divide them all by the highest survivorship rate in the whole population. So they will all be scaled from 0 to 1.

Or, if you’re looking at the proportion of individuals that reproduces compared to the rest, you might want to check out “selection coefficient” or “selection differential,” they might fit the bill.